Converging/Diverging Front Intake

ABSTRACT

An air supply system for a refrigerator cabinet, which reduces temperature differences through-out the cabinet generates air currents in the cabinet by a panel that extends across the inside of the cabinet. The panel is set an angle that directs air downwardly and terminates with an upwardly-inclined air-diverting surface or baffle. The panel and baffle define a converging/diverging air intake for the air supply system, the input of which is located at the front of the refrigerated cabinet.

BACKGROUND

Commercial refrigerator cabinets in common use today provide arefrigerated interior region with shelves that hold products to be sold.A problem with prior art commercial refrigerators is that it isdifficult to provide uniform airflow within the cabinet. Air currentsfrequently develop such that regions of the cabinet are colder thanothers. A cool-air supply system that provides a more uniform cold airdistribution within a refrigerator cabinet would be an improvement overthe prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a refrigerator cabinet;

FIG. 2 is a front elevation of the refrigerator cabinet shown in FIG. 1;

FIG. 3 is side view of the refrigerator cabinet shown in FIG. 1 and FIG.2; and

FIG. 4 is a side view of the refrigerator cabinet depicting aconverging/diverging front intake, which aids in the even distributionof refrigerated air flow in the refrigerator cabinet.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a refrigerator 100. The refrigerator 100is comprised of a first or left side 101 (not visible in FIG. 1), asecond or right side 102, a third or top side 104, a fourth or bottomside 106 (not visible in FIG. 1), a rear panel 108 and a front door 110.Wheels 112 attached to the bottom side 106 enable the refrigerator 100to be rolled about. The front door 110 pivots on two hinges 114 locatedat and attached to the top edge 116 and bottom edge 118 of the door 110,which enable the door 110 to be opened by grasping a handle 120. Thedoor 110 provides access to the interior of the refrigerator 100 wherefood items are to be refrigerated.

A thin, inclined, substantially planar air-diverting panel 150 islocated inside the refrigerator 100 and fixed in the refrigerator 100.The panel 150 is mounted in the refrigerator at an angle relative tohorizontal, which was empirically determined to aid in the deflection ofair currents inside the refrigerator 100 and significantly reducetemperature differences through-out the refrigerator 100.

In a preferred embodiment, the panel 150 is made of thin sheet metal. Inan alternate embodiment, the panel 150 is made of plastic. The panel 150is preferably a solid sheet, however, in alternate embodiments the panel150 is perforated with holes or slots.

The panel 150 is sized, shaped and arranged to extend from close to thebottom of the refrigerator and close to the door, inwardly and upwardlyinto the refrigerator 100 to a lower rear surface 152 of the interior ofthe cabinet. Stated another way, the panel 150 extends outwardly anddownwardly from the lower rear surface 152 toward the bottom of therefrigerator, near the door 110.

When the panel 150 is viewed from the lower rear surface 152, the panel150 appears to be declined relative to horizontal. Stated another way,the panel 150 is inclined at a negative angle relative to the lower rearsurface 152. When the panel is viewed from the door 110, the panel isinclined relative to horizontal.

The panel 150 preferably abuts both the between the left side 101 andthe right side 102 of the refrigerator 100. The panel 150 also extendsalmost all the way from its point of attachment to the lower rear panel152 to the front door 110.

A downward-sloping portion of the panel 150 terminates or “ends” at anedge 154, best seen in FIG. 3, beyond which there extends a relativelyshort, inclined planar surface referred to herein as a “baffle” 156. Theedge 154 constitutes a line of demarcation between the downwardlysloping panel 150 and the upwardly sloping baffle 156. Experiments showthat the panel 150 formed with the edge 154 and baffle 156, reducetemperature gradients in the refrigerator. The panel 150, edge 154 andbaffle 156 are believed to operate collaboratively to direct cold aircurrents in the cabinet upwardly in the cabinet. The panel 150, edge 154and baffle 156 also define an air passage 158, which when viewed fromthe side converges to a narrow point just below the edge 154 and thendiverges defining in the process, a venturi wherein air pressure isreduced.

FIG. 2 is a front elevation of the cabinet shown in FIG. 1. The panel150 can be seen extending between and abutting the first or left side101 and the second or right side 102 of the refrigerator 100. An airpassage 158 exists in the open space between the edge 154 and bottomsurface of the refrigerator 100.

An air circulation fan 200 is located proximate the top surface 104 ofthe cabinet. It is mounted in an upper back wall 202 of the refrigerator100 and is configured with ducting to pull air through an evaporatorcoil (not shown) behind the back wall and into the refrigerator, i.e.,toward the door. The fan 200 thus drives air into the interior of therefrigerator 100 creating a positive pressure inside the refrigerator100 relative to the volume below the panel 150.

FIG. 3 is a side view of the refrigerator 100. The fan 200 can be seenmounted into the top portion of the upper back wall 202 to pulls chilledand therefore relatively dense air (identified by arrows labeled withreference numeral 304) through an evaporator 306 behind the upper backwall 202. The cold air 304 flows downwardly in the cabinet, i.e. towardsthe panel 150. When the cold air 304 reaches the panel 150, it strikesthe panel 150, flows over the panel 150 toward the front edge 154 andtoward the baffle 156. Since the baffle 304 is a solid or virtuallysolid surface, air 304, which continues to fall downwardly, is believedto curl upwardly from the baffle 156 in a counterclockwise rotation asshown by reference numerals 304. The curl of the air flow thus providesa turbulence, which deflects at least some of the air 304 upwardly inthe cabinet.

Those of ordinary skill in the art will recognize that the cold andrelatively dense air from the fan 200 creates a slightly positivepressure in the interior volume 306 of the refrigerator 100. Air flowsinto the fan 200 after being drawn through the evaporator 306. And, airflows into the evaporator from a duct 314 defined by the rear panels152, 153 and 202 of the refrigerator 100. Air flows into the duct 314from a plenum 316 formed by the sloping panel 150. Air flows into theplenum 316 from the interior 306 of the refrigerator 100 after passingthrough the narrow air passage 158 defined by the lower edge 154 and thebottom 106 of the refrigerator 100. The narrow air passage 158 defines aventuri. The duct 314 thus draws air from the plenum 316 and routes theair into the evaporator 306, back to the fan 200. The fan 200 thus actsas a cold air supply.

Those of ordinary skill in the art will recognize that the fan 200creates a negative pressure inside the plenum 300, the duct 314, and theevaporator 306 at the same time that it creates a positive pressureinside the cabinet interior. Air 304 in the interior 306 of therefrigerator 100 thus eventually flows over the distal end 314 of thebaffle 156, through the venture, continually circulating responsive tothe fan 200.

Air that flows over the distal or farthest end 314 of the baffle 156flows into a converging nozzle 320 formed by the baffle 156 and therelatively flat bottom surface 106. The converging nozzle 320 terminatesat the lower edge 154 of the panel 150, which defines the aforementionedpassage 158, which is also where the lower edge 154 creates the venturi.Air flows through the passage 158 and into the plenum 316 where theupwardly inclined panel 150 defines a diverging nozzle 322.

In tests of the refrigerated refrigerator 100, it was determined thatthe panel 150 improves cold air distribution in the interior 306 of therefrigerator 100. The upwardly inclined baffle 156 is believed toredirect air current as described above.

In the preferred embodiment, the panel 150 and baffle 156 are made froma single solid panel of thin sheet metal, which is stamped or folded todefine the edge 154. Alternate embodiments include the use of a singlepanel of sheet metal that is stamped or rolled such that the edge 154 isactually curved or arcuate. Curved edges 154 include those which aresubstantially elliptic, substantially parabolic or substantiallycircular.

The panel 150 and baffle 156 are preferably made from a solid panel ofsheet metal. Alternate embodiments use a panel 150 and baffle formedfrom perforated metal or plastics, perforations of which are so small asto be impervious or substantially impervious to air flow in order tohave the panel 150 and baffle 156 be able to deflect air currentseffectively.

The panel 150 and baffle 156 preferably extend all the way between theleft side 101 and the right side 102 of the refrigerator 100. Alternateembodiments include the use of a panel and hence the use of aconverging/diverging nozzle that does not extend all the way to thesides but instead leaves a small open space on one side, the other orboth. Other alternate embodiments include the use of multiple panels,i.e., two or more panels, inclined at the same or different angles andmounted side-by-side each other in the refrigerated space.

The rear panels 152, 153 and 202 conduct or route air from the plenum316 back to the evaporator 306. The rear panels 152, 153 and 202 thusdefine a warm air return duct. The warm air return duct thus effectivelyroutes the air supplied by the fan 200 back to the evaporator.

Those of ordinary skill in the art will recognize that when the fan 200is operating and drawing air through the passage 158 near the front door110, a low pressure zone exists in front of the passage 158. The door110 thus prevents the induction of warm room air into the plenum 316 andto the evaporator 306. In order to improve thermal efficiency, in oneembodiment, an interlock switch is operatively coupled to the door 110,the switch being configured to shut-off power to the blower 200 wheneverthe door 110 opens.

The panel 150 is fixed in the refrigerator 100 at an angle ofapproximately negative 15 degrees relative to horizontal, with theorigin of the angle being defined by the intersection of the panel 150with the lower rear surface 152 of the cabinet. The negative fifteendegree angle was determined experimentally due to the fact that foodstorage shelves, commonly used in refrigerated cabinets are inclined atan angle of approximately fifteen degrees. The fifteen degree angle ofthe panel 150 thus conforms to the inclination of storage shelves usedin the refrigerator 100. Alternate embodiments of the cool air supplysystem that is depicted in the figures and described above have panelsfixed at steeper and flatter angles. In one extreme, the panel 150 canbe inclined at about negative 80 degrees up to about positive 80degrees.

As shown in the figures, the baffle 156 is inclined relative tohorizontal at an angle of approximately 30 degrees, the origin of thatangle being at the front edge 154 of the panel 150. Alternateembodiments include having a baffle 156 at angles that are between aboutzero degrees and vertical or 90 degrees relative to horizontal.

Those of ordinary skill in the art will recognize that the panel 150 andbaffle 156 define an angle between them. As shown in the figure, thepanel 150 and baffle 156 define an angle between them of about 120degrees. Alternate angles between those two structures range from aboutjust under 180 to 90 degrees.

The foregoing description is for illustration purposes. The scope of theinvention is set forth in the appurtenant claims.

1. An air supply system for a refrigerator cabinet, the refrigeratorhaving an interior defined by first and second sides, a rear side, afront opening, a top and a bottom, the air supply system comprising: atleast one panel extending between the first and second sides of theinterior and extending from proximate the rear side of the interiortoward the front opening, the at least one panel having a front edgeproximate the front opening and having an inclined surface that extendsupwardly from the front edge at an angle, the at least one panel, frontedge and baffle defining an air passage proximate the front opening. 2.The air supply system of claim 1, wherein the at least one panel and thebottom of the refrigerator cabinet comprise a converging/divergingnozzle.
 3. The air supply system of claim 2, wherein theconverging/diverging nozzle extends substantially all the way betweenthe left and right sides.
 4. The air supply system of claim 3, furthercomprising: an evaporator configured to cool air passing through theevaporator; fan configured to move air through the evaporator; and awarm air return duct that carries air between the converging/divergingnozzle and at least one of the fan and the evaporator.
 5. The air supplysystem of claim 4, wherein the warm air return duct is comprised of theat least one panel and an interior surface of the refrigerator.
 6. Theair supply system of claim 4, wherein the cabinet is further comprisedof a door, pivoting on a hinge proximate to one of the left and rightsides of the cabinet.
 7. The air supply system of claim 6, furthercomprising: a blower, configured to move air through the cabinet; and aswitch operatively coupled to the door, the switch being configured todisable the blower when the door is open.
 8. The air supply system ofclaim 1, wherein the at least one panel is fixed at a first angle,relative to horizontal.
 9. The air supply system of claim 8, wherein thefirst angle is between about negative ninety degrees to about positiveninety degrees.
 10. The air supply system of claim 1, wherein the baffleis at a second angle, relative to horizontal.
 11. The air supply systemof claim 10, wherein the second angle is between about zero degrees andninety degrees, relative to horizontal.
 12. The air supply system ofclaim 1, wherein the at least one panel is fixed at a first anglerelative to horizontal, the baffle is inclined at a second anglerelative to horizontal, the panel and baffle defining a third anglebetween them, the third angle being between zero degrees and ninetydegrees.
 13. The cool air supply system of claim 1, wherein the at leastone panel is perforated.
 14. The cool air supply system of claim 13,wherein the at least one panel is perforated and wherein the at leastone perforated panel is substantially impervious to air.
 15. The coolair supply system of claim 1, wherein the at least one panel abuts atleast one of the left and right sides.
 16. The cool air supply system ofclaim 1, wherein the at least one panel abuts the rear surface.
 17. Thecool air supply system of claim 1, wherein space between front edge, thebaffle and the bottom define a venturi.
 18. A method of circulating airin a refrigerator having an interior with first and second sides, a rearsurface, a front, a top and a bottom, the method comprising the stepsof: driving cold air into the interior; and collecting warm air througha converging/diverging nozzle located proximate the bottom, theconverging/diverging nozzle being comprised of the bottom and, a panellocated between the first and second sides and extending from proximatethe rear surface of the interior toward the front opening, the panelhaving a front edge proximate the front opening and having a baffleextending upwardly from the front edge at an angle.
 19. The method ofclaim 18, wherein the converging/diverging nozzle extends substantiallyall the way between the first and second sides.
 20. The method of claim18, further comprising the step of: returning warm air to the cold airsupply through a duct connected between the converging/diverging nozzleand the cold air supply.